Figure 6. 17-year-old female ballet dancer. (a) Sagittal spin echo T1 weighted MR image (TR/TE, 722/20) shows low T1 signal within the medial sesamoid. In addition there is a smooth break in the cortex of the sesamoid (arrow), in keeping with a bipartite sesamoid. (b) Sagittal short tau inversion recovery MR image (TR/TE/TI, 4655/30/130) shows high signal in the medial bipartite sesamoid (arrow) in keeping with sesamoiditis.